1. Field of the Invention
The present invention relates to a one-piece injection molded binder for securing together a plurality of sheets.
2. Description of the Related Art
Conventional one-piece binders include a longitudinal dorsal part and fingers spaced along the dorsal part. The fingers form rings which run through punch holes in the sheets to secure the sheets together. The dorsal part and the rings are made of a single piece of flexible plastic. The fingers overlap the dorsal part, so the sheets cannot slide and fall out of the rings.
The above-described binders are conventionally punched out of sheets of polyvinylchloride (PVC), then heated and rolled into a cylindrical shape. In the cutting process, approximately 15 percent of the initial sheet material is lost as surplus as a result of cutting the sheets into strips, punching the binders, and cutting the binders to length. PVC is the best suited material for the punching and rolling process, but it poses serious environmental issues since it creates hazardous gases when incinerated.
The round profile of the binder created through the above-noted rolling process causes the stack of bound sheets to have a convex profile, particularly when large diameter binders are employed. This phenomenon detracts from the aesthetics of the finished bound document, because the unbound edge assumes the convex shape of the round binding material, such that the bound material often extends beyond the cover and the back of the binder.